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Funding and Awards --> Cecil
H. and Ida M. Green Technology Innovation Awards
--> 2005 Abstracts
Abstracts of 2005 Cecil H. and
Ida M. Green Technology Innovation Awards
A New Broadband, Low Cost, High Resolution Side-Scan
Sonar for Small AUV's
Dezhang Chu and Tom Austin
As
small AUV’s become more popular, the need grows
for high quality, low cost sensors that are specifically
designed to support the specific size, power, and cost
constraints of these vehicles. This proposal combines
a newly developed ultra-miniature high frequency sonar
transceiver with a novel broadband acoustic transducer
design to significantly improve the imaging quality
possible from a very low cost sonar imaging system.
Broadband
sonar system can be used for a variety of acoustic applications
in ocean explorations, ranging from seafloor mapping,
to sub-bottom profiling, and to water column mapping.
However, to fabricate wide-band acoustic transducers
with flat and uniform spectra is a challenging task,
especially when a consistent spectrum is required in
applications involving broadband acoustic arrays. A
new approach is proposed to construct broadband transducers
using a spectrum-matching method, in which the frequency
response or power spectrum will be designed to match
the inherent frequency characteristics of the PZT ceramics.
With this approach, the spectrum of the transducer can
be controlled simply by the geometric shape of the ceramics
relative to the known spectrum of a reference transducer,
and hence a wide band and smooth spectrum can be achieved.
By incorporating the state of art electronics developed
previously and a side-scan sonar array consisting of
the broadband transducer elements developed through
this proposal, we will build and test a broadband, low
cost, and high resolution side-scan sonar mounted on
a small AUV (REMUS).
Helical
Turbine Generators for Moored Applications
Donald Peters and Matthew Naiman
Power
for oceanographic instrumentation on moorings can be
derived from a number of sources. For surface moorings,
a combination of solar panels and storage batteries
is a common and effective way to generate and store
power. Commercially available wind generators can also
be used for power generation. However, both solar panels
and wind generators are vulnerable to damage on a surface
buoy, and in some locations lack of sun limits the effectiveness
of solar panels. At high latitudes in particular, harsh
conditions, icing, and low sunlight availability make
solar and wind power poor choices for long-term power
generation. The purpose of this proposal is to study
the viability of Gorlov helical turbines as an alternative
power generation source on oceanographic moorings.
Gorlov
helical turbines are actuated by the flow of water,
and are novel in that their direction of rotation is
always the same, regardless of incoming flow direction.
On surface moorings, an element on the mooring some
distance from the surface experiences not only the ambient
horizontal flow from wind and tidal currents, but also
an oscillating vertical flow produced by the heave of
the surface buoy. A properly oriented helical turbine
could derive power from all of these flow components
simultaneously. One goal of the proposed work is to
develop a mounting arrangement for these turbines that
makes the best use of the available flow, and to study
ways of enhancing that flow. The other goal is to investigate
techniques for extracting electrical power from the
turbines, in a way that is both mechanically simple
and electrically efficient.
Developing
Compound-Specific Stable Bromine Isotope Measurements
C. Reddy, L. Ball, R. Nelson, S. Sylva
Brominated
organic compounds (BOCs) are important molecules involved
in climate change, human and marine mammal health, and
chemical ecology. We believe that studying the subtle
changes in the ratios of the stable bromine isotopes,
79Br and 81Br, will be an effective tool and add to
the field. To achieve the latter, this proposal requests
funds to build an interface between a gas chromatograph
(GC) and an inductively coupled plasma mass spectrometer
(ICP-MS), which will allow us to measure the bromine
isotope ratios on individual compounds. We will also
develop standards and perform initial experiments. This
novel approach will be useful by many scientists interested
in the source, transport, and fate of BOCs in the environment.
We hope to use this support to provide enough data for
an initial publication as well as a much larger NSF-style
proposal.
Raman
Spectroscopy for In Situ Mineralogical Analyses
Sheri N. White and Meg Tivey
In-situ
sensors capable of real-time measurements and analyses
in the deep ocean are necessary to fulfill the potential
created by the development of autonomous, deep-sea platforms
such as AUVs and cabled observatories. Raman spectroscopy
is an optical technique which is capable of in situ
molecular identification of solids, liquids, and gases,
and is well suited to extreme environments. At present,
it is not possible to identify the chemical composition
of minerals in situ. Raman spectroscopy has been used
successfully for mineral identification in the laboratory.
The development of a sea-going Raman system capable
of deployment on an ocean observatory or AUV will allow
the in situ analysis of minerals that are deposited
and precipitated at hydrothermal vent sites. This will
provide insights into processes occurring in the subsurface
which affect ocean chemistry.
The
goal of this proposal is to perform the background analyses
and research necessary to obtain funding for the development
of a small-scale laser Raman spectrometer specifically
designed for in situ mineralogical analyses in the deep
ocean. Many rocks and minerals found in the deep ocean
(e.g., basaltic components and hydrothermal minerals)
are Raman active. Laboratory measurements (both at WHOI
and in collaboration with scientists in NH) will be
made to determine the optimal characteristics for a
deep-sea mineralogical Raman system. These include excitation
wavelength, spectral range, and sensitivity. Commercial
“hand-held” Raman systems will also be investigated.
The long-range goal is development of a mineralogical
Raman system small enough to be deployed on an AUV.
A
Re-Determination of the 14C Half-Life
Mark Roberts
In
1960, the Nobel Prize in chemistry was awarded to W.F.
Libby for “his method to use carbon-14 for age
determination in archaeology, geology, geophysics, and
other branches of science”. Integral to Libby’s
work was the determination of the 14C half-life. Today,
the accepted half-life of 14C is 5700 years ±
30 years (National Nuclear Data Center, Brookhaven National
Laboratory). This value is the weighted average of values
obtained from specific activity measurements. Recently,
based on apparent systematic trends and offsets in the
radiocarbon calibration curve (cf., Reimer, 2004), questions
have been raised as to the validity of the ‘accepted’
14C half-life (Broecker, 2005a and 2005b). A significant
shift in the 14C half-life impacts not only archeology
and paleo-oceanography, but also modern estimates of
planetary scale thermohaline overturning rates and abyssal
biogeochemical fluxes. Moreover, such a change requires
revision of estimated cosmogenic nuclide production
rates over the past 50,000 years. Although there are
no specific reasons to doubt the current 14C half-life
value, an alternative approach to determining its value
would be an important and conclusive test of Broecker’s
hypothesis. We propose a novel method to measure the
14C half-life that does not rely upon a specific activity
measurement. Using a high-energy accelerator, we will
implant a known number of 14C ions into a silicon based
beta spectrometer. The beta spectrometer will then be
removed from the accelerator and operated in a ‘self-count’
mode to determine the number of implanted 14C atoms
that decay in a given time. With precise knowledge of
the initial number of atoms implanted and the resulting
number of 14C decays per unit time, the half-life of
14C can be determined.
Toward an Image-Based Cell Sorter for Plankton
Research at Ocean Observatories
Robert J. Olson
We
propose to explore a way of combining these approaches,
so that individual cells can be sorted and then manipulated
to provide information beyond identification. In this
way we can study more directly the mechanisms behind
the species distributions we observe. The need for this
type of sampling capability was recently highlighted
at an international National Ocean Partnership Program
(NOPP) workshop on marine ecogenomics. Specifically,
we propose here to use miniature solenoid valves to
sort microplankton cells automatically, by momentarily
redirecting a sample stream through a re-usable nylon
mesh, where the cells will be exposed to a fluorescent
DNA stain and then imaged by a CCD camera. Our longer
term goal is to incorporate this laboratory prototype
into our new submersible imaging flow cytometer, where
real-time identification of individual cells will provide
the basis for sorting decisions.
Preparation
of Carbon Dioxide for Radiocarbon Analysis from Marine
Dissolved Organic Carbon
Li Xu and Ann P. McNichol
Radiocarbon
(14C) is a powerful tracer for global carbon cycling
studies. The advent of accelerator mass spectrometry
(AMS) 25 years ago revolutionized radiocarbon analysis
and opened the field to many more research areas. Radiocarbon
studies of all the carbon pools in the ocean are providing
insights into the transfer of carbon in the ocean. Dissolved
organic carbon (DOC) plays an important role in carbon
cycling in marine environment and studies of its radiocarbon
content will provide valuable information in identifying
its sources and estimating the turnover rate of organic
carbon in the marine system. Currently, the method to
measure 14C in DOC is not routinely available in most
AMS labs, including the National Ocean Sciences Accelerator
Mass Spectrometry Facility (NOSAMS). We propose to develop
a method to analyze 14C in marine DOC, in order to benefit
carbon cycle researchers, both inside and outside WHOI.
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